Active material for a positive electrode of a battery cell, positive electrode, and battery cell

Abstract

A positive active material for a positive electrode of a battery cell which includes a first component containing a compound of general formula: Li_2-zNa_zM¹_1-yM²_yO₃, where M¹ and M² are different from one another and stand for transition metal ions, 0<y<1, and 0≤z<2, with the condition that the compound is essentially free of manganese ions. Moreover, a positive electrode of a battery cell which includes the positive material, and a battery cell which includes at least one positive electrode, are also described.

Description

[0001]The present invention relates to a positive active material (A) for a positive electrode of a battery cell which includes a first component (A1) containing Li2M11-yM2O3, M1 and M2 independently standing for transition metal ions that are not manganese ions. Moreover, the present invention relates to a positive electrode of a battery cell which includes an active material (A) according to the present invention, and a battery cell which includes at least one positive electrode according to the present invention.BACKGROUND INFORMATION[0002]The storage of electrical energy has become increasingly important in recent decades. Electrical energy may be stored with the aid of batteries. Batteries convert chemical reaction energy into electrical energy. A distinction is made between primary batteries and secondary batteries. Primary batteries are non-rechargeable, while secondary batteries, also referred to as accumulators, are rechargeable. A battery includes one or multiple battery c...

AI Technical Summary

Benefits of technology

[0038]Due to the use of an active material (A) that includes a first component (A1) of formula Li2-zNazM11-yM2yO3 that is essentially free of manganese ions, an active material (A) for positive electrodes of battery cells may be provided which ensures a stable voltage over a relatively long time period and a large number of cycles when used in a lithium-ion battery cell. Likewise, the capacity of the lithium-ion battery cell remains stable over a relatively long time period and a large number of cycles. Losses in voltage and capacity are significantly reduced. The service life of the battery is thus increased, thus enabling commercial use in particular of lithium-ion batteries with an NCM compound in active material (A) of the positive electrode.

Problems solved by technology

However, these and conventional HE-NCM materials are characterized in that they deliver high cell voltages at the beginning of the service life of the cell, but over the service life are subject to significant losses (so-called “voltage fade”).

This results in irreversible oxygen loss in the active material, which is accompanied by destabilization of the material due to the resulting defects in the material structure of the active material.

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